China National Offshore Oil Corporation (CNOOC) is implementing the comprehensive adjustment project at the Caofeidian 11-1/11-6 oil field located in Bohai Bay off the coast of China.
Situated at a water depth of 20m-25m, the expansion project was brought onstream in November 2019. It is operated by CNOOC, which holds 51% and 60% working interest in Caofeidian 11-1 and Caofeidian 11-6 oilfields respectively. Brightoil Petroleum has a 40.09% interest in Caofeidian 11-1 and a 29.18% interest in Caofeidian 11-6 while the remaining stake in the fields is owned by SPC E&P (China).
The field is anticipated to reach its peak production capacity of approximately 28,700 barrels per day in 2021.
Development history of Caofeidian Oil Field
The field was discovered in 2000 by the then operator Kerr-McGee, which co-owned the field along with partners Newfield Exploration and Sino-American Energy.
First oil from the Caofeidian 11-1/11-2 field was produced in July 2004. The peak production capacity of the field was 40,000 to 45,000 barrels of oil per day. Caofeidian 11-3/5 fields in block 04/36 started production with the peak capacity of 13,800 barrels of oil per day in November 2005. The fields were later combined with the Caofeidian 11-1/11-2 field to improve the economics.
The Caofeidian 11-6/12-1S fields, which started production in October 2006, have a peak capacity of six million barrels of oil a year.
Details of the Caofeidian oilfield expansion project
The expansion project involved the development of two large central processing platforms, CEPJ and CEPI, weighing approximately 11,000t and 13,000t respectively.
The CEPJ platform jacket was constructed by COOEC, a subsidiary of CNOOC, at its yard in Qingdao. The CEPI module is an eight-legged, steel structure with three-layer main deck. The floating installation of CEPI module for the Caofeidian 11-1/11-6 was performed using Offshore Oil 228.
It also uses the existing oilfield facilities, including six wellhead platforms and a 900ft-long floating, production, storage, and offloading (FPSO) vessel, Hai Yang Shi You 112. The vessel has the capability to process up to 80,000 barrels of oil. It can store up to one million barrels of oil to further offload in tankers.
A total of 89 producer wells are planned to be undertaken, of which 12 are producing as of November 2019.
Existing Caofeidian oilfield details
The Caofeidian 11-1/11-2 is located in a water depth of 20m in block 04/36 in the western Bohai Bay. The FPSO vessel, Hai Yang Shi You 112, is the main production platform of the field.
The initial field development involved a 48-slot wellhead gathering platform and a wellhead platform with 24 slots.
The Caofeidian 11-6/12-1S fields, located in 04/36 and 05/36 blocks, featured three wellhead platforms, including two unmanned satellite platforms, during the development. The produced crude oil is transported to the FPSO via a 13km-long subsea pipeline. The crude oil from the Caofeidian 11-3/5 is produced using an unmanned facility.
Other offshore oilfield projects of CNOOC
CNOOC started production in Huizhou 32-5 oil field comprehensive adjustment/Huizhou 33-1 oil field joint development situated in the eastern part of the South China Sea in January 2019. Located at a water depth of 115m, the project has peak production of 19,200 barrels of oil equivalent per day (boe/d).
The Egina oilfield in Nigeria with 200,000boe/d peak production was also brought online in the same month, while the Appomattox in the US Gulf of Mexico began production in May 2019. The company flowed first oil from the Bozhong 34-9 oil field in February 2020.